code: def singleton(cls):
      """Decorator to ensures a class follows the singleton pattern.
  
      Example:
          @singleton
          class MyClass:
              ...
      """
      instances = {}
  
      def getinstance():
          if cls not in instances:
              instances[cls] = cls()
          return instances[cls]
  
      return getinstance
  
file_path: wandb/wandb/vendor/watchdog_0_9_0/wandb_watchdog/utils/decorators.py
imports: import functools
  import warnings
  import threading
  import sys
label_desc: Use image node_id 5 for calling a global function with example usage: singleton(cls) and returns: getinstance, instances